Monsanto Co. (MON) raised its earnings outlook for the year on strong demand for corn seed as U.S. farmers plan to plant a huge crop this spring.

The world's largest seed company said second-quarter earnings jumped 19% over a year ago, due in large part to its corn seed and traits business. Net sales in that business, which increased 17%, were buffeted by higher volumes and demand for higher-priced seeds, as well as unusually warm winter weather that fueled early seed shipments.

Federal forecasters last week projected U.S. farmers will plant the most corn acreage since 1937 to take advantage of continuing strong prices for the grain.

While Monsanto's earnings beat expectations, it was less clear to what extent the early sales in the second quarter will result in slower sales later in the year.

"How much of the great quarter is linked to timing, and how much is linked to actual performance in our business, it's difficult to measure at this point in time," Chief Financial Officer Pierre Courduroux said in a conference call with investors.

He said that earnings in the second half of the year would likely be flat versus a year ago. Still, the company was confident enough to raise its full-year earnings guidance to $3.49 to $3.54 a share, an increase of 10 cents a share.

Investor reaction was muted, as analysts said the new guidance was squarely within Wall Street expectations. Shares were recently down 1.2%, to $80.80 amid a broader market slump.

The St. Louis-based company reported increased sales across its top three businesses: corn, soybeans and agricultural productivity, which includes Roundup and other herbicides.

Monsanto in 2010 suffered through a backlash from farmers, who balked at the company's high initial price for its new premium corn seed, SmartStax. The problems were compounded by what was seen as a disappointing performance in the seed's first year, and the share price fell sharply.

Monsanto has since "made a conscious effort to address product choices and pricing to better connect" with customers, Grant said. Sales of the company's premium corn seed products so far this year are at the high end of expectations, he said.

Monsanto executives sound more humble than they did a couple years ago, said Mark Connelly, an analyst with CLSA. He added that Grant and other officials seem wary of building expectations too high. Rather than focusing on one particular seed for one particular region, it is emphasizing growth across geographic regions, including South America.

"Monsanto is not trying to be a one-hit wonder," Connelly said. "They are trying to convince you they have a long-term, sustainable growth story."

For the quarter ended Feb. 29, Monsanto, based in St. Louis, reported a profit of $1.21 billion, or $2.24 a share, up from a year-earlier profit of $1.02 billion, or $1.88 a share. Stripping out items like a settlement, earnings per share rose to $2.28 from $1.87 a year earlier.

Net sales rose 15%, to $4.75 billion. Analysts were looking for earnings of $2.12 a share on $4.53 billion in sales, according to a poll conducted by Thomson Reuters.